SGI 011
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Polar Wander and Global Tectonics
K.M. STORETVEDT (*)
ABSTRACT
Evidence suggests that irregularly-distributed degassing of the Earth has produced lateral physico-chemical variations in the mantle which in
turn have instigated changes in the planet’s moments of inertia. Intermittent events of spatial reorientation of the globe (polar wander) and a
mixture of continual and episodic changes of planetary spin rate have ensued. Thus, the developing lithosphere has time and again been subjected
to stepwise latitude-dependant torsion (wrenching) producing fold belts along time-equivalent equators, with a second set of tectonomagmatic rift
belts evolving in palaeomeridional settings. Due to Earth’s rotational slowing through time, the rift belts – oriented orthogonal to, and breaking
away from, their corresponding palaeoequators – were of much greater significance in the Precambrian than during the Phanerozoic. However, in
the course of time the global tectonic pattern has changed in concurrence with events of polar wander – the equatorial bulge and associated fold
belt have now and then shifted their position across the globe. The relatively fast-spinning Archaean Earth had approximately its present spatial
setting, but at around the Archaean-Pro-terozoic boundary a major event of polar wander took place, heralding a significant change in Earth
history. Inertia-driven continental rotations, producing the presently-observed discrepancies in palaeomagnetic polar wander paths, basically
dates from the time of the Alpine climax.
KEY WORDS: Planetary degassing, Moments of inertia,
Polar Wander, Earth’s rotation rate, Gross pattern of
tectonic belts.
INTRODUCTION
It appears that it was the Austrian geologist A. Damian Kreichgauer who first suggested a dynamic link between
global tectonics and the Earth’s rotation (KREICHGAUER, 1902). Kreichgauer discovered the pole-fleeing force, i.e. the
combined effect of the dynamics of Earth rotation and the principle of isostasy, later named the Eøtvøs force (EØTVØS,
1913). This equatorward force of crustal motion, directed away from the poles (Polflucht), would have produced fold belts
in general alignment with time-equivalent equators, while a second set of tectonomagmatic belts would have evolved in
meridional settings – owing to the westward directed tidal drag from the Sun and Moon. Based on a straithforward
interpretation of ancient climates derived from rocks and fossils, polar wander seemed a necessity. For dynamical reasons,
the rotational axis had to be aligned along, or to remain in the vicinity of, the principal axis of inertia: it became, therefore,
an inevitable conclusion that internal axial shifts had intermittently occurred during the Earth’s history. In other words, the
apparent displacement of the pole over the surface was a result of the Earth’s body
(*) Institute of Geophysics, University of Bergen, N-5007 Bergen, Norway – Fax: +47 55 58 98 83; email: karsten@gfi.uib.no
intermittently turning over relative to space. In the mid 1950s the principle of polar wander was confirmed by
palaeomagnetism (CREER et alii, 1954; RUNCORN, 1955).
In the Kreichgauer dynamic system, the required changes in the Earth’s axes of inertia were brought about by the
equatorward and westward displacements of the entire crust, without significant lateral continental motions. Changes of
the relative position of the palaeoequator would then have given rise to tectonic belts in variable orientations across the
globe. Thus, by combining palaeoclimatic observations with the observed global tectonic system, for different geological
epochs, Kreichgauer was able to draw polar paths that show remarkable similarities to modern polar wandering curves
based on palaeomagnetic data (STORETVEDT, 1997, 2003). In Kre-ichgauer’s scheme, the meridional ‘mountain belts’ were
rifted zones (Strichen) trending at approximately right angles to their corresponding downfaulted and compressed
equatorial seating – the classical geosynclines – constituting an elongated crustal depression (Äquatormülde) around the
globe. Fig. 1 shows the palaeoequators for the late Proterozoic (a) and late Archaean (b) respectively, drawn by
KREICHGAUER (1902).
Reflecting on the battle surrounding the interpretation of palaeomagnetic data in the late 1950s, it is difficult to
understand that the prominent English pysicists, at the principal scenes of fact gathering and global geomagnetic
discussion, did not consider seriously (if at all) the role of inertia effects as the adequate driving force for continental
mobility – to account for intercontinental palaeomagnetic discrepancies. After all, Kreichgauer’s global model –
explaining prominent aspects such as the repositioning of the global climate system through time, the phenomenon of
polar wander, and the shifting tectonic configuration since the Precambrian – had in fact a much greater explanatory power
than Wegener’s continental drift or any other global tectonic model, past and present. Regarding palaeoclimatology and
polar wander Wegener built extensively on Kreichgauer’s work, but being a meteorologist he was basically ignorant about
geology and tectonics, and therefore he overlooked Kre-ichgauer’s tectonic scheme. It is important to note that
Kreichgauer’s continental arrangement is still valid to a good first order approximation, as the needed changes of
continental azimuths, to account for intercontinental palaeomagnetic discrepancies, are only minor (S TORETVEDT, 1990,
1997, 2003). In any case, it certainly required no deep perception on Wegener’s part to see that Kreichgauer’s model was
at variance with his own pet idea: lateral continental motions. Thus, preconception was certainly an important part of the
reason why Wegener rejected much of Kreichgauer’s work, accusing him of having a muddled understanding of Earth
history.
K.M. STORETVEDT
Fig. 1 -Tentative orientation of the palaeoequator for two different different Precambrian epochs, based on a combination of ancient climates
(from rock evidence) and the location of time-equivalent tectonomagmatic belts: (a) late Proterozoic and (b) late Archaean. Simplified after
KREICHGAUER (1902).
But drifting continents clearly provided a more ‘dramatic’ and entertaining story than the fairly ‘static’ crustal model of
Kreichgauer, and probably for that reason alone, Wegener’s book was translated into several languages, including English,
while Kreichgauer’s work does not seem to have reached beyond the German speaking world. One may wonder what
would have been the outcome had Kreichgauer’s treatise, rather than Wegener’s, been translated into English and then
been available to the British palaeomagnetists in the mid-1950s. After all, the latitude-dependant inertia forces invoked by
Kreichgauer, would be liable to produce in situ rotations of the continental lithospheric blocks in recent geological time
[basically of late Cretaceous to early Tertiary age] – providing the cause of the observed discrepancies between the
established polar wander paths. However, the principal palaeomagnetic workers of the 1950’s and 60’s were so blinded by
Wegenerian-type lateral motion, that they failed to recognize the alternative inertia-driven mobilistic system.
The present author has always sheared the view that the overall pattern of global palaeomagnetic data underpins the
concepts of polar wandering and relative continental motions. But owing to the many apparently unsolvable complications
associated with Wegenerian-type continental fittings and the never-ending flow of ad hoc provisions in plate tectonic
depictions, I was already in the early 1970s in search for an alternative dynamo-tectonic framework. By 1989 my
long-time speculations regarding the dynamo-tectonic ‘system of the Earth’ eventually paid off – a radical recasting of the
association of many well-known phenomena and observations, dismissing all plate tectonic principles, was about to take
shape (STORETVEDT, 1990, 1992). It was the compelling need to find an alternative way of making sense of global
palaeomagnetic data that ultimately led to a new theory of the Earth – Global Wrench Tectonics (STORETVEDT, 1997,
2003). All of a sudden, changes of planetary rotation had become a key facor for understanding tectonics as well as a
range of other facets about the Earth. WEGENER (1929/1966) had referred to Kreichgauer’s book, a volume that was not
available at my university, or could be traced elsewhere in Scandinavia. During a study visit to the Geological Institute in
Innsbruck in May 2000 I had for the first time the opportunity to read Kreichgauer’s book. To my surprise, I found that the
link between Earth’s rotation and global tectonics, a central element in my Global Wrench Tectonics, had already been
outlined by him a century ago. Kreichgauer compared the orientation of tectonomagmatic belts with time-equivalent
equators based on rock evidence of palaeoclimate. My own starting point had been a combination of
palaeomagnetically-estimated continental palaeolatitudes and kinematics, polar wandering based on combined fossil
climate evidence and palaeomagnetism, and the global pattern of tectonomagmatic belts. To account for the shifting axis
of inertia, with associated polar wander, Kreichgauer adhered to tide-driven transposition of some outer crystalline layer,
assuming that the Earth’s interior had reached thermo-chemical equilibrium at an early stage – an assumption that, as
against present evidence, can no longer be supported.
The interior of the Earth must provide the energy source for its dynamics and surface physiographic and geological
change. In view of the apparent heterogeneous deep interior inferred from modern mantle tomography – including deep
mantle roots beneath the continents, the presence of diamonds in chaotic mantle rock assemblages explosively emplaced
into surface levels, the continuous flow of unoxidized hydrocarbons through the crystalline crust, and the increase in rock
porosity with depth in the crust provide strong evidence for a relatively cold interior undergoing degassing. In other words,
evidence suggests that the planet’s internal constitution is far from being in chemical equilibrium, and that the body of the
Earth has, since its very beginning, been striving to attain such a state. Based on this starting point we have a new basis for
understanding changes in the planet’s moment of inertia, with aligned polar wandering, and above all we have thereby
established an effective driving mechanism to instigate geological processes.
THE INTERNAL MACHINERY
With regard to the formation of the solar system, the old idea of the planets having developed from relatively
homogeneous co-rotating nebular disk eddies – the planetesimal theory – still prevails, even though the many failures and
the various ad hoc exceptional provisions surrounding this scenario (CAMERON, 1962, 1978, 1985; LEVY, 1987; BOSS,
1990) strongly indicate that an adequate understanding of the planetary system’s evolution has yet to be drafted. An
adequate sequence of events may run as follows (STORETVEDT, 2003):
a) The planets formed from condensation of individual rotating spherical masses of cold concentrated gas and mineral
dust in variable proportions, expelled from the contracting and rotating protosun. Owing to the turbulent expulsion forces,
the various proto-planetary objects attained differing angular momenta. Thus.
b) The Earth aggregated from a rotating ‘ball’ of cold nebula material enriched in mineral constituents – being
transformed into a proto-planet through progressive conglomeration of essentially micrometer- to smaller-sized
condensates. The transfer of groups of particles within the relatively dense mineral cloud was affected by dynamic,
gravitational and magnetic forces.
c)A significant proportion of heavier elements in the cold proto-planetary cloud, including radioactive elements like
Thorium and Uranium, was forced dynamically towards the outer geosphere were gradual decay of unstable isotopes gave
rise to heating. On the other hand, magnetic attraction between ferromagnetic particles and clusters led to their coalescence
into large and irregular bodies upon which gravitational forces outweighed dynamic ones. Thus, aggregations of
magnetized iron particles expectedly led to the gravitational accretion of the heavier inner body – gradually building up a
central core dominated by iron or iron alloys.
d) The outcome of this early mass segregation was an outer region heating up through radioactive decay processes
while the deeper interior remained in its relatively cold state. However, differential tidal variation between core and mantle
is likely to have led to frictional heating and partial melting within the core-mantle boundary zone – the D” layer, leading
to further transfer of ferromagnetic material into the high-conductivity outer core, while the bulk of the mantle – due to its
lower thermal conductivity – is likely to have remained in a relatively cold state with slow chemical reaction rates.
e) Owing to the suggested relatively low temperatures of at least the bulk of the silica-rich mantle, degassing of its
largely undifferentiated interior – in its run towards thermo-chemical equilibrium – can be expected to have been a slow
process that is still in progress.
In the new theory of the Earth – Global Wrench Tectonics – it is the slow internal degassing, with its associated mass
transfer processes (see STORETVEDT, 2003), which provide the ‘engine’ for planetary change. Dynamical segregation
within the inferred relatively fast spinning pre-consolidated proto-Earth produced a thick pan-global felsic
(anorthositic-dioritic) cover layer without a distinct lower boundary. There are reasons for believing that, within the
gas-filled protoplanet, coalescence of ferromagnetic planetesimals – through gravitational and magnetic accretion
processes (TUNYI et alii, 2001, 2004) – gradually led to heavier concretions for which the gravitational influence
outbalanced the centrifugal effect. In consequence, the heavier iron-rich masses settled inwards through the relatively less
dense gaseous mass, gradually building up a high-density core. However, as elements like sulphur, carbon, silicon,
hydrogen and oxygen easily dissolve in high pressure metallic mixes (S TEVENSON, 1981; HUNT, 1992; OKUCHI, 1997),
these lighter constituents can be expected to have followed iron alloys into the core. Furthermore, as the gravitational
pressure at depth must have increased as a consequence of iron alloy migration, any fraction of free hydrogen may have
been turned into a metallic state, adding additional substance to the inferred well-known density deficit of the core (relative to expectation). According to GOTTFRIED (1990), the core must be the host of a significant amount of hydride-metal
compounds while the silicate-rich lower mantle must include an appreciable volume of silicides, notably silicon carbide
(SiC). As some high pressure form of silica may be an important constituent of the lower mantle, T SUCHIDA & YAGI (1989)
carried out high pressure studies of heated α-quartz. The experiments showed that, under pressure conditions assumed for
the lower mantle, silica transforms to the slightly denser form stishovite or a similar phase. Thus, in order to attain
gravitational stability, stishovite would have to transform into a much denser structure, combining for example with MgO
to form perovskite currently believed to be the dominant mineral in the lower mantle (POIRIER, 2000). In any case, with the
many lighter elements now regarded as possible constituents of the deep Earth, it is of paramount importance to consider
the geodynamic and geological consequences of buoyant volatiles – including a range of hydrocarbon compounds –
escaping from the Earth’s core.
Owing to its high abundance ratio, silicon may be a very important element of the core’s metal hydrides, its low
density giving it differential buoyancy. In this manner, masses of less-dense metal hydrides can ascend in the mantle,
probably representing one of the most important mechanisms of internal mass reorganization – instigating planetary
change. Following this line of thought, the interior of the Earth has been subjected to slow degassing, with associated
outwardly directed element transport, leading to substantial chemical and mineralogical transformation of the primordial
felsic incrustation, along with implantation of the Moho and an irregular asthenospheric layer (STORETVEDT, 2003). In this
process, hydrous fluids caused overpressures within the outer regions, producing upwardly migrating eclogitization and
associated gravitational instability of the transformed felsic rocks – thereby thinning the lighter cover layer from the
bottom upwards (STORETVEDT, 2003).
According to STEVENSON (1981), the core is not in equilibrium with the mantle, and the presence of an irregular D”
topography (MORELLI & DZIEWONSKI, 1987) is further evidence of a thermo-chemically active and heterogeneous zone.
Due to a combination of chemical and tidal heating, it appears likely that buoyant masses arise from the
topographically-elevated segments of the D” zone. Fig. 2 shows that, when projected onto the Earth’s surface, regions of
the core-mantle layer that stand proud correspond to deep oceanic depressions. This observation may hint at the possibility
that processes at the outer core and/or D” layer release energy as well as buoyant masses which eventually lead to
chemical transformation, crustal thinning, and formation of deep oceanic depressions. The irregular degassing from the
deep Earth ought to produce systematic differences between continental and oceanic mantles – in composition,
temperature and porosity – giving rise to variations in seismic velocities. Thus, the degassing Earth model seems to readily
account for the seismic evidence for deep continental roots – reflecting a relatively clear distinction between continental
and oceanic mantles (MACDONALD, 1964; DZIEWONSKI, 1984; FORTE et alii, 1995).
On the question of upward transfer of energy from the core-mantle boundary layer, GREGORI (2001) considered the
potential of ‘topographic’ elevations to initiate tidal heating. He suggested that electrical currents would
K.M. STORETVEDT
Fig. 2 -Diagrams demonstrating topography of the core-mantle boundary obtained by inversion of PcP residuals (upper), PKP residuals (middle),
and the two data sets combined (lower), corrected for lower mantle heterogeneity. Simplified from MORELLI & DZIEWONSKI (1987).
concentrate on the top of such ‘bumps’ releasing anomalous amounts of heat which, due to the presumed low thermal
conductivity of the silicate mantle, does not propagate. Thus, Gregori described the upward-directed transfer of energy as
electrodynamic rather than thermodynamic, and as resembling an electric soldering iron being pushed into a block of ice.
In the presence of sufficient concentration of pore spaces – kept open by the high internal gas pressures – Gregori’s
mechanism may provide an efficient way of mantle degassing and internal elemental reorganization.
Diamonds, the high pressure form of carbon, are neither stable nor in equilibrium at low pressures, but when
transported rapidly to the surface – driven by the high internal gas pressures – from their source in the mantle, diamonds
can survive long enough to avoid being converted into the low-pressure form of graphite. The fact that natural diamonds
or diamondiferous kimberlites (an ultrabasic rock of mantle provenance) may contain inclusions of SiC or unoxidized
carbon-bearing fluids (MELTON & GIARDINI, 1974; LEUNG et alii, 1990), and that methane and other hydrocarbons are being
emitted continuously through the crystalline basement (W ELHAN & CRAIG, 1983; MCLAUGHLIN-WEST et alii, 1999; LUPTON
et alii, 1999) provide strong prima facie evidence that the internal temperature is over all relatively low. Hence,
throughout its history, the Earth must have been out of thermo-chemical stability. Therefore, in the natural process of
reaching such an equilibrium state, mass reorganization – aided by buoyant volatiles – must have been at work since the
planet’s very beginning. These operations have given rise to a progressive reorganization of interior mass – triggering
episodic inertia-driven changes of planetary rotation, with the associated evolutionary course of spasmodic geological
activity.
CHANGES OF THE EARTH’S ROTATION
The moment of inertia of a rotating body is a way of expressing the concentration of its mass about the centre of
gravity. The greater the concentration of mass, the greater its moments of inertia, and the faster the body will spin. Thus,
any net inward motion of mass increases the Earth’s moment of inertia and therefore increase its rate of rotation; similarly,
any net outward (equatorward) mass transport decreases the moment of inertia and reduces the planet’s spin rate. For
example, the gradual magneto-gravitational accretion of the core referred to above, interchanging angular momentum
between the proto-core and the proto-mantle, would have led to increasing planetary spin, adding to the ‘preset’ high rotation rate presumed for the pre-consolidated Earth (ALFVEN & ARRHENIUS, 1976). An observation supporting the hypothesis
of a relatively faster spin velocity in the geological past (than now) is that the present Earth has a certain excess flattening,
making its equatorial bulge some 200m larger than that expected. M UNK & MACDONALD (1960) suggested that this
non-hydrostatic bulge is a relic of a faster rate of rotation in the past, the lag in gaining hydrostatic equilibrium being
ascribed to the high viscosity of the mantle. However, long-term internal degassing, producing upward mass transfer, has
inevitably caused planetary slowing, increasing the length of day. Compilation of growth rings in fossil shells (C REER,
1975) has similarly unfolded progressive, but variable, slowing of the Earth’s rotation over the past 500 Ma.
The build-up of high volatile pressures in the outer shells of the planet evidently has triggered eclogitization – causing
gravitational instability of the chemically transformed shell – eroding the crustal layer from the bottom upwards.
Therefore, at particular times in the Earth’s history, periods of crustal uplift, releasing over-pressured volatiles, alternating
with crustal subsidence – the latter being triggered by the sinking of masses of heavier eclogitized crustal material to some
lower level of the (presumed) low-viscosity upper mantle – would inevitably have generated periodic acceleration of the
planet’s spin rate. As shown by CREER (1975) these sharper changes of rotation rate – break-points for which periods of
enhanced deceleration have alternated with periods of acceleration – correspond to the well-established global tectonic
events. According to Global Wrench Tectonics it is the ‘jerks’ in planetary spin rate that triggers torsion of the pan-global
lithosphere, turning the time-equivalent palaeoequatorial belts into overall transpressive (or transtensive) tectonic regimes,
along with occasional rifting along palaeomeridian sections.
As long as the major axis of inertia – the axis of figure
– stays near the astronomical spin axis, the relative polewill have a fairly stationary position (G OLDREICH & TOOMRE,
1969). According to the degassing model, however, suggesting that irregular redistribution of internal mass has taken
place since Archaean times – inevitably changing the orientation of the inertia axes – it is to be expected that, from time to
time, the Earth’s body must have turned over relative to the ecliptic. We have already associated global tectonics per se
with changes in the rate of planetary rotation and, in the furtherance of that idea, it can be predicted that certain
palaeoequatorial belts have been the sites of ancient fold belts, and that major rift structures have evolved in perpendicular
(i.e. palaeomeridional) settings. This extended link between tectonics and the Earth’s palaeorotation may therefore be the
key to solving a basic and long-standing problem in geology: the temporally shifting position of large-scale zones of
structural deformation and magmatic activity across the globe.
ORIGIN OF FUNDAMENTAL FRACTURE SYSTEMS
Based on the consideration above, it can be assumed that in the early Archaean heating from combined radiogenic,
tidal and chemical processes gave rise to an effective degassing of the outer few hundred kilometres of the Earth,
accompanied by the installation of partial melt pockets at upper mantle levels – representing the embryonic stage of the
present-day irregular asthenospheric zone – while the deeper parts of the planetary body are likely to have maintained
largely their original low temperatures. Aided by buoyant volatiles, the outer regions of the geosphere – including
present-day upper mantle – were depleted of a number of incompatible and other elements, to be correspondingly enriched
in the surface layer, resulting in mineralization, plutonism, greenstone belt volcanism, and pervasive potassium
(metasomatic) granitization of the crust. These processes were particularly momentous in Upper Archaean and earliest
Proterozoic times, probably having impressed strong and widespread remobilization and isotopic age resetting of older
rocks. Furthermore, by late Archaean times, the Earth’s surface regions had apparently cooled significantly; hence, the hot
and ductile state of the early-mid Archaean outer shell had been replaced by more brittle conditions. Increasing
solidification of the outer layers, combined with cooling and sustained planetary degassing, then led to brittle fracturing.
First of all, cooling gave rise to a minor amount of planetary shrinking which, in turn, catalysed deep great-circle
contraction dislocations – the disrupted remnants of which one of them are to be seen in the present-day peri-Pacific
Benioff system.
Evidence suggests that the relatively fast-spinning cooling Archaean Earth (undergoing a minor degree of contraction)
had approximately its present spatial orientation (STORETVEDT, 2003), and therefore one would expect to observe clear
differences in structure of the Benioff zone between the present-day eastern and western Pacific borders – at low to
intermediate latitudes. Thus, a fast-spinning late Archaean Earth, with an outer crystalline layer being subjected to
westward-directed inertia drag, would be liable to produce a compressive and relatively shallow-inclined cooling fracture
in the direction of planetary rotation (i.e. as per the present-day eastern Pacific), while tensional conditions and a relatively
steeply inclined cooling fracture would result in the wake of that motion (corresponding to the western Pacific). These
predictions are fully confirmed by the distinct differences in structure and seismotectonics observed between eastern and
western Pacific Benioff planes.
With the progressive build-up of upper mantle gas pressures, producing a certain pan-global extensional ‘surface’
regime, along with the increasing brittleness of the cooling late Archaean crust, the time was ripe for implantation of
tension fractures. It is suggested that these conditions set the scene for the development of the omnipresent orthogonal
fracture systems which formed along palaeomeridians and palaeolatitudes, respectively. Thus, the development of this
orthogonal rupture system expectedly had a close connection with planetary rotation; on the basis of a relatively fast
spinning Archaean Earth, it is reasonable to think that outgassing was strongest along the palaeoequatorial belt (owing to
the maximum centrifugal effect along that ‘plane’) and that the orthogonal rupture system expanded from that zone
towards higher palaeolatitudes. Thus, a simple pan-global tectonic fabric was established – inculcating a structural
anisotropy of ultimate importance for subsequent geological development. Once formed, these fractures would be prone to
repeated rejuvenation and intensification throughout the Earth’s dynamo-tectonic history – the latter being controlled by
more distinct changes in planetary rotation instigating lithospheric wrenching.
The combined gas pressure build-up – causing surface upheaval – and subsequent sub-crustal attenuation in
association with upper mantle gas release leading to crustal subsidence, must have produced a distinct
‘expan-sion-contraction’ pulsation of the globe. Moreover, the preset fracture network would affect the architecture of
subsequent fold belts. Following the theory of Global Wrench Tectonics, the most extensive tectonic belts have developed
along their time-equavalent palaeoequators. Therefore, segments of such belts that fall along one of the two fundamental
fracture sets will be expected to display relatively smooth elongate geometries, while those parts of the tectonic belt that
cut across the preset elongate fracture network will form a ruptured en echelon structure.
According to the new theory of the Earth, the most important phase of wrench deformation of the outer layers –
including relative in situ rotations of the remaining continental masses (i.e. those parts of the surface layer that had not
been significantly affected by ‘oceanization’ processes) – took place in Alpine time. Therefore, by applying world-wide
joint orientation data established by Adrian Scheidegger and numerous coworkers (S CHEIDEGGER, 1995, for a review),
correcting them for Alpine-age continental rotations established by palaeomagnetic data (S TORETVEDT, 1990, 1992, 1997),
it should be possible to retrace the spatial palaeo-setting of the globe and the initial orientation of the conjugate orthogonal
fracture sets.
K.M. STORETVEDT
Fig. 3 -Strike directions for one of the characteristic orthogonal joint axes as established on different continents. Plots are on a Mercator
projection and after correction for Alpine age in situ continental rotations, but without altering continental azimuths. These corrected joint trends
will intersect close to the present geographic poles, thus defining a system of longitudes. Similarly, the nearly E-W striking orthogonal set of
fractures will specify a system of parallels. In other words, the original configuration of the ubiquitous orthogonal joint sets formed a simple
global pattern – representing a system of palaeogrids probably implanted during the Upper Archaean. From S TORETVEDT (2003).
The outcome of such an exercise is shown in fig. 3, depicting the inferred strike directions of one of the characteristic
orthogonal joint axes. When extended across the globe, these corrected joint trends will intersect close to the present
geographic poles, defining a system of longitudes. The similarity with Kreichgauer’s late Archaean palaeoequator (fig. 1b)
is striking. Similarly, the nearly east-west striking orthogonal set of joints (not displayed in the diagram) will specify a
system of parallels.
The Upper Archaean was the time of formation of the greenstone belts, and the massive amount of magmatism
associated with these elongate zones of depression – having developed along particular zones of weakness, corresponding
to the already established network of orthogonal fractures – suggests that upper mantle upwelling and interior mass
reorganization was at force. Therefore, at some stage, the maximum axis of inertia would have changed sufficiently to
bring about an inevitable spatial reorientation of the planet. Such a resetting of the equatorial bulge, along with a greater
polar flattening due to a faster spin velocity at that time, would have produced extensional conditions, notably in the new
intermediate-low palaeolatitude regions, giving rise to intrusions into the preset orthogonal fracture network. Attendant
increase in the exhalation of water vapour, carbon-diox-ide and hydro-carbon gases (in association with organometallics,
eventually depositing ore concentrations) would naturally result.
There are reasons for believing that such a profound change in global dynamics took place at around the
Archaean-Proterozoic boundary, loosely dated at ca. 2.5 Ga, heralding a major change in Earth history. From then on,
carbonate deposits became more widespread, life became more abundant, major sedimentary basins with banded iron
formations developed, and more modern-type tectonomagmatic belts gradually replaced the Archaean greenstone belts
(WINDLEY, 1995).
THE WRENCH TECTONIC SYSTEM DURING THE PROTEROZOIC
The question arises as to the spatial position in which the Earth eventually settled after the inferred dynamic instability
around the Archaean-Proterozoic boundary. In principle, palaeomagnetic data should provide adequate information to this
question, but unfortunately published results for these early times constitute a jungle of inconsistent and undoubtedly
unreliable data. Remagnetization and unresolved multi-component remanences are likely to feature prominently in older
rocks – as can be judged from the unjustified disparities in shape of the pre-Lower Palaeozoic polar paths for the
Atlantic-bordering continents. Nevertheless, one may wonder whether the predicted turning over of the Earth’s body at
around 2.5 Ga ago occurred in a single event or had a more protracted stepwise progression. In this regard, Neoproterozoic
palaeomagnetic poles from the northern cratonic regions define reasonable clusters at antipodal positions of ca. 65ºE, 20ºN
and 115ºW, 20ºS respectively (STORETVEDT, 1997). With the continental masses in their pre-Alpine azimuthal orientations
this late Precambrian palaeoequator runs along Arctic Canada and Labrador Sea (fig. 4), further along present-day Central
and South Atlantic (fig. 5), it ‘touches’ present-day Antarctica, cuts through Australia, continues across north-western
Pacific, before rejoining the Arctic Canada branch. This Upper Precambrian palaeoequator, defined by palaeomagnetic
evidence, is surprisingly similar to the one proposed by KREICHGAUER (1902) on a completely different basis (fig. 1a). It
should not come as a great surprise if this palaeoequator actually had remained relatively unchanged for the entire
Proterozoic. The rational behind that prediction is that, during the Precambrian, the rate of internal mass reorganization
apparently was relatively slow making polar wander a rare phenomenon. In fact, it is thought that the inferred Proterozoic
palaeoequator remained relatively unchanged until around mid-Ordovician times during which another major event of
polar wander occurred, providing a fundamental shift of the tectonic pattern across the globe.
The Proterozoic-Lower Palaeozoic palaeoequator can be linked to many important tectonic features. Thus, many
elongate mobile zones with a spread of late Precambrian to Lower Palaeozoic ages, exposed on present-day continents,
show overall near-perpendicular orientations with respect to the inferred palaeoequator, suggesting that they originated as
ensialic transtensivetranspressive crustal bands in response to changes of planetary spin rate. However, the
palaeo-equatorial girdle, with its aligned fold belt, is largely positioned in pre-sent-day oceanic regions, having been
disrupted by later events of crustal thinning and ‘basification’ processes and concealed eventually by oceanic sediment and
water masses. In fact, the late Precambrian to early Palaeozoic equatorial zone (with its aligned fold belt) is only exposed
in the Arctic Canada to Labrador Sea sector and through Central Australia – the latter transect comprising the Adelaide
Geosyncline and Warburton-Georgina-Bonaparte basins.
Fig. 4 -The (late) Proterozoic to Lower Palaeozoic (pre-450 Ma) equator seen in conjunction with recognized Grenvillian (ca. 1 Ga) and
Cadomian (ca. 600 Ma) tectonic provinces of the Arctic and North Atlantic regions. The land masses are in their pre-Alpine azimuthal
orientations. Apart from the insular region of Arctic Canada, the palaeoequator-aligned (circum-globe) fold belt is located within present-day
oceanic regions, but a range of late Proterozoic metamorphics have been recovered from the Central Atlantic Ridge (see STORETVEDT, 1997, 2003
for data base). Note that the principal Arctic-North American lithotectonic belts have near-perpendicular orientations with respect to their
time-equivalent equator, indicating that they formed through rifting and shearing during events of global lithospheric torsion. This
latitude-dependent wrench deformation, which has its maximum effect along the (palaeo)equator, is indicated by curved solid arrows.
Abbreviations are: G.P., Grenville Province; M.R., Mid-continent Rift; W.C., Western Cordillera; F.I., Franklin-Innutian Belt; E.G.,
Ellesmerian-North Greenland Belt; S.N., Sveco-Norwegian Belt.
A substantial proportion of the Proterozoic anorogenic magmatic rocks in the world occur in a broad belt across the
North American continent, from Labrador to southern California (EMSLIE, 1985). In the wrench tectonic system, this
magabelt – dated to around 1.4 Ga (GOWER et alii, 1990) – would be connected to a transtensional regime brought about by
one or more events of planetary deceleration (STORETVEDT, 2003). Such tectonically rather quiet conditions apparently
came to a close at around 1.3-1 Ga after which time renewed planetary acceleration gave rise to enhanced wrench
deformation, reactivating many pre-existing rifts. The most famous of these major late Proterozoic lithotectonic zones is
the Grenville Province, the main deformation of which occurred around 1 Ga (S CHAERER & GOWER, 1988), extending from
coastal Labrador to south-western USA. With the time-equivalent equator passing across the Arctic Canada-Labrador Sea
region (fig. 4), the present NESW striking set of fundamental crustal discontinuities, originally oriented approximately
N-S, was in line for strong reactivation. The Grenvillian phase of rifting and associated shearing may indeed have affected
the entire
Fig. 5 -The inferred Proterozoic to Lower Palaeozoic equator seen in conjunction with the main segments of the Pan-African and Brazilian
tectonomagmatic provinces. The continents are in their pre-Alpine setting. Abbreviations are: A.B., Amazon Belt; M.B., Mauritanides Belt;
C.A.B., Central African Belt; D.B., Damaran Belt; C.B., Cape Belt. Other specifications are as for fig. 4. After S TORETVEDT (2003).
North American craton, extending west beyond the pre-sent-day Canadian Cordillera (COOK, 1995). If the Grenville
Province became transpressively deformed in response to planetary acceleration (eastward), the evolving tectonic belt
ought to have a western west-directed thrust front. Such a western frontal upthrust is indeed a characteristic feature of the
Grenville Province, and COCORP seismic profiling across the tectonic zone of the Grenville Front (G REEN et alii, 1988;
CULOTTA et alii, 1990) has revealed a 30 km wide frontal zone dipping ca. 30º to the south-east and extending at least to
Moho depths.
With the Grenvillian event having affected the whole of present-day North America, thousands of kilometres away
from the actual palaeoequator, it would be logical to think that it also contributed similar large-scale ensialic rifting into
the opposite palaeohemisphere – cutting across the present-day North Atlantic, which formerly was a continental domain.
Following this line of thought the late Precambrian to Lower Palaeozoic segments of the Pan-African and Brazilian
lithotectonic belts (fig. 5) can be readily accounted for; the embryonic East African Rift and the Trans-Antarctic belt can
be similarly explained.
Nowadays, it is generally believed that the Sveco-Nor-wegian tectonic sector in southern Scandinavia represents a
direct continuation of the Grenville belt proper (STARMER, 1993; ANDERSEN, 1997), but such a close
K.M. STORETVEDT
Fig. 6 -Palaeoclimatically based equators for three differents time intervals: Carboniferous (C), Permian (P) and Lower Tertiary (LT). Based on
descriptions by KREICHGAUER (1902) and WEGENER (1929).
lithotectonic correlation does not necessarily apply. In fact, during Grenville time, global wrenching not only affected
Europe along the Sveco-Norwegian sector, but also the basement of south-western England, the Channel Islands and of the
European Alps were all subjected to strong tectonomagmatic reactivation at that time (N EUBAUER et alii, 1989; POWER et
alii, 1990). In particular, the European sector of the deep great-circle Archaean-age contraction dislocation – along which
the Tethyan Basin and, finally, the Alpine-Himalayan belt developed – would have been prone to repeated rifting and
wrench deformation in Proterozoic and Lower Palaeozoic times. This is equivalent to the prolonged Proterozoic and
younger tectonic history of the western Cordillera of North America (STORETVEDT, 2003).
From Grenville time onwards, the Earth is presumed to have experienced several changes in its rate of rotation. An
example of such a predicted change may have occurred in Vendian to Middle Ordovician time when the protracted
Cadomian deformation phase developed, in consequence of which belts of Grenvillian age around the world would have
been liable to repeated overprintings, encompassing both transpressive and transtensive events. In the Humber Zone of
Newfoundland, for example, Grenvillian basement units occur as significant discrete massifs, and rocks from late
Precambrian rifting in that region (diabase and granite intrusions) give radiometric ages of around 600 Ma (W ALDRON et
alii, 1998). In the European sector, polyphase magmatism, deformation and metamorphism have similarly been reported
(NEUBAUER et alii, 1989; BROWN et alii, 1990; DALLMEYER et alii, 1992).
EVENTS OF PHANEROZOIC POLAR WANDER AND ASSOCIATED FOLD BELTS
The Earth’s spatial orientation was apparently quite steady during the Proterozoic and well into the Lower Palaeozoic,
but recurrent tectonic activity during this ca. 2 Ga long period suggests that progressive degassing gave rise to shorter-term
oscillations of the planet’s rotation rate. Therefore, it would only be a matter of time before the consequent transformation
of the Earth’s interior mass would have changed the moment of inertia sufficiently to propel an event of polar wander.
Such a geodynamic revolution took place at around mid-Ordovician time during which the Earth’s setting, relative to the
ecliptic, changed by about 70º. Since the Silurian, the Earth has experienced a number of progressive polar shifts – the
palaeoequators having formed a age-progressive southward system oriented at right angles to the present Greenwich
meridian, defining two regions of mutual intersection at the present equator, at around 90ºW and 90ºE (S TORETVEDT, 1997,
2003, and references therein). A simple presentation of this palaeoequatorial/polar wander system, without correction for
the moderate in situ continental rotations that occurred in Alpine time, is delineated in fig. 6. However, before the Earth
had settled into this simple time-progressive arrangement, there was – according to palaeomagnetic evidence
(STORETVEDT, 1997) – a specific transition period in the Upper Ordovician; during this period, the palaeoequator had a
more northerly trend, passing along the northern North Atlantic and Barents Sea regions with a south-east-erly
continuation across Central Siberia.
Degassing in a rotating Earth would have produced certain concentrations of fluid flow along palaeo-equator-ial belts
giving rise to more effective sub-crustal erosion and the formation of coaxially-aligned sedimentary troughs
(geosynclines). In the European sector, the late Ordovician (Taconic) equator was sufficiently separated from the
‘Devonian’ (Acadian) equator to form two separate Caledonian segments: an Arctic branch and a north central European
division. In the North American sector, however, the two palaeoequators were much closer together and, therefore, they
merged into a united elongated geosyncline-tectonic zone.
The orientation of the linear Lower-Middle Palaeozoic sedimentary trough that evolved along the eastern seaboard of
North America was clearly predetermined by the prevailing north-easterly structural grain (i.e. present – post-Alpine –
azimuthal orientation). It formed along, and the developing tectonic processes interfered, in part, with the Grenville
Province proper which – within a different palaeotectonic setting – had formed some 800-600 Ma earlier. According to the
fossil ‘clock’ data compiled by CREER (1975), the Lower-Middle Ordovician was a time of planetary deceleration which,
theoretically, should have produced overall transtensional conditions within the world-encircling Appalachian-Caledonian
tectonic belt, thereby paving the way for increased regional magmatic activity. Thereafter, from the latest Ordovician and
throughout the Devonian, the Earth seems to have experienced overall acceleration. Hence, the associated forces of inertia
would have led to overall transpressive conditions along the palaeoequatorial geosyncline, providing adequate explanations for both the Taconic and Acadian phases of deformation. However, the compressive forces were not strong enough to
produce anything but insignificant crustal thickening – in other words, the amount of sub-crustal thinning that led to
formation of the Appalachian-Caledonian geosyncline was not compensated for by the transpressive processes that turned
the sedimentary trough into a mobile belt. This lack of tectonic crustal thickening along fold belts is well demontrated by
seismic profiling across the Newfoundland Appalachians (J ACKSON et alii, 1998).
Sectors of the globe-girdling belt that fall along one of the preset orthogonal fracture lineaments would naturally attain
a relatively smooth outline. On the other hand, in regions where the palaeoequator cuts across the actual conjugate system
of fractures, the evolving tectonic zone would not attain a smooth equator-aligned construction, but rather develop an en
echelon structure, occasionally taking more marked offshots, as rifted zones, along one of the fundamental fracture
systems. This is apparently the explanation of the East Greenland-Svalbard branch(es) of the Caledonides, as they take on
more northerly excursions away from the north-easterly course of the time-equivalent equator.
Fig. 7 depicts the pre-Alpine reconfiguration of the present northern continents, along with the late Precambrian and
mid-Palaeozoic equators. One notes that the Appalachian and trans-European tectonic belts line up with the Middle
Palaeozoic equator suggesting a common tectonic history at least in Acadian time. According to C REER (1975), the
Siluro-Devonian time was one of acceleration, and the associated inertia effects may therefore be related to the
Salinic-Acadian phases of crustal-lithospheric deformation. The thick curved arrows in fig. 7 demonstrate the resulting
inertial motions, with clockwise torsion in the northern palaeohemisphere and counter clockwise torsion in the southern
palaeohemisphere. This dynamo-tectonic system readily explains major fault zones that run parallel or sub-parallel to
many fold belts, e.g. the North Anatolia Fault Zone in the Alpine belt, and the Great Glen and Cabot faults in the
Caledonian-Appalachian tectonic system. The mid-Palaeozoic wrench deformation would naturally have led to strong
reactivation of the fundamental conjugate fracture system of eastern North America (originally oriented approximately
N-S, but upon the Alpine-age lithospheric wrenching it has acquired a NE-SW axis), and it is likely that the north-easterly
trending zonation within the Newfoundland Appalachians primarily owes its origin to extensive strike-slip motions along
the tectonic belt at that time. The several kilometres of Moho offset, seen across the north-eastern extension of the Dover
Fault (separating the Newfoundland Appalachian belt from the Precambrian Avalon block to the south), suggests that the
extended Dover Fault represents a major strike-slip fracture. Within the overall transpressive regime of the Acadian
deformation belt, one might expect that stress-induced remelting would have occurred in places, and that associated
intrusive activity would have developed in areas of localized transtension (MILLER et alii, 2001; STORETVEDT, 2003).
At later stages of Earth history, notably from the late Jurassic onwards, attenuation and basification processes
(‘oceanization’) of the original dioritic-felsic crust advanced more rapidly than before so that, by the early Tertiary, the
deep oceanic depressions were approaching their present global distribution. In concert with the pronounced mechanical
weakening associated with the major crustal-lithospheric thinning, the ensuing geodynamic event – the Alpine revolution
– pitched the Earth into a tectonic calamity. During this period, inertia-driven relative continental rotations occurred for
the first time in the Earth’s history, producing significant deformation and faulting within the thin and mechanically weak
oceanic crust.
In the pre-Alpine azimuthal orientation of the continents (STORETVEDT, 1997, 2003), the southward extension of the
Caledonian-Appalachian fold belt runs through southern Mexico, cuts into the north-western tip of the South American
Andes, continues along a main segment of the present East Pacific Rise, further along
Fig. 7 -Pre-Alpine configuration of the North Atlantic depicting the position of the Grenville/Sveco-Norwegian terranes and the
Appalachian/North-Central European Caledonides. The corresponding palaeoequators are shown for comparison. Note again that the late
Precambrian to early Palaeozoic equator (1) has a near-orthogo-nal setting in relation to the Grenville and Sveco-Norwegian provinces,
suggesting that they are segments of megascale rift zones. On the other hand, the mid-Palaeozoic palaeoequator (2) is closely aligned to the
mid-Palaeozoic branches of the trans-Atlantic Appalachian/Caledonian fold belt. Note that the Sveco-Norwegian Province occurs at asimilar
distance from the Precambrian equator
(1) as the ‘westernmost’ extension of the Grenville Province proper.Solid arrows demonstrate the global wrenching in mid-Palaeozoic time,
giving rise to the palaeoequator aligned Appalachian/North-Central Caledonian belt. From STORETVEDT (2003).
Fig. 8 -In the pre-Alpine azimuthal orientation of Australia, the late Proterozoic equator becomes co-linear with the Adelaidean lithotectonic zone
(A.B.), but is cut in turn by the younger Tasman belt (T.B.) which represents a segment of the globe-girdling, palaeoequa-tor-aligned
Caledonian/Appalachian tectonic structure. In this consideration, the Tasman-Adelaidean tectonic junction has its antipodal counterpart in the
tectonic junction of the Newfounland region depicted in fig. 7. From STORETVEDT (2003).
the Tasman fold belt in Australia, proceeds across Asia before finally linking up with its Arctic and North Atlantic
segments discussed above. Thus, in the pre-Alpine continental arrangement, the Caledonian-Appalachian belt runs in close
agreement with the early-mid Palaeozoic equatorial zone. Fig. 8 delineates the locations of the late
K.M. STORETVEDT
Precambrian and mid-Palaeozoic equators viewed in conjunction with the pre-Alpine orientation of Australia. Note that
these palaeoequators fall along the Adelaidean and Tasman fold belts respectively. The Tasman-Ade-laidean tectonic
junction has its antipodal counterpart in the Newfoundland region where the late Precambrian to early Palaeozoic equator
intersects the mid-Palaeozoic equatorial zone at a fairly steep angle (fig. 7).
According to the global tectonic system advanced here, the principal tectonomagmatic belts are to be found in two
palaeogeographic settings: either as deformed geosynclines, running approximately along time-equivalent equators, or as
rift zones breaking out at steep angles from their respective palaeoequators. The principal operating forces in the formation
of these structural belts are a combination of the centrifugal force of rotation, the pole-fleeing force, the Coriolis force, and
the tidal effects of the Moon and Sun. Thus, the tectonic arrangement versus geological time has, generally speaking,
followed the shifting relative position of the equatorial bulge; i.e. the phenomenon of polar wander is intimately associated
with both regional and global tectonic development.
Inferentially, the Precambrian Earth had a rotation rate that was a good deal faster than it is now and, as a thin and
mechanically weak oceanic crust had not yet been formed, the surface layer must have been relatively brittle in the context
of mechanical forces. For these reasons, the late Precambrian rift zones – exemplified by the Grenville Province, the
Pan-African belts, and the East African Rift System – are all of relatively large dimension compared to their
post-Precambrian relatives, such as the Oslo Graben, North Sea Graben and Rhine Graben.
CONCLUDING REMARKS
The new global tectonic framework – Global Wrench Tectonics – submits that the principal tectonomagmatic belts on
Earth, with their temporally shifting locations, are intimately related to changes of planetary rotation, being the product of
both variations in spin velocity and shifts in the planet’s spatial orientation (with respect to the ecliptic). In essence, all
tectonomagmatic structures around the globe seem to have developed through intermittent processes of lithospheric
torsion (wrenching) associated with planetary degassing and related internal reorganization of mass. The main tectonic
structures have defined either (a) globe-encircling mobile belts running in close alignment with time-equivalent equators,
or
(b) rift structures (or grabens) oriented at steep angles to
– and spreading away from – these palaeoequators. Thescale of these rift structures has diminished through geological
time, in concert with the protracted slowing of the Earth’s rotation.
REFERENCES
ALFVEN H. & ARRHENIUS G. (1976) -Evolution of the Solar System. National Aeronautics and Space Adminstration, Washington D.C.
ANDERSEN T. (1997) -Radiogenic isotope systematics of the Herefoss granite, South Norway: an indicator of Sveconorwegian (Grenvillian)
crustal evolution in the Baltic Shield. Chem. Geol., 135, 139-158.
BOSS A.P. (1990) -Solar Nebula Models: Implications for Earth Origin. In Origin of the Earth, Oxford Univ. Press, Oxford.
BROWN M., POWER G.M., COPLEY C.G. & D’LEMOS R.S. (1990) -Cadomian magmatism in the North American Massif. In The Cadomian Orogeny,
Geol. Soc., London.
CAMERON A.G.W. (1962) -The formation of the Sun and Planets. Icarus, 1, 13-69.
CAMERON A.G.W. (1978) -Physics of primitive solar nebula and giant gaseous protoplanets. In Protostars and Planets, Univ. of Arizona Press,
Tucson.
CAMERON A.G.W. (1985) -Formation and evolution of the primitive solar nebula. In Protostars and Planets II, Univ. of Arizona Press, Tucson.
COOK F.A. (1995) -Lithospheric processes and products in the southern Canadian Cordillera: a Lithoprobe perspective. Can. J. Earth Sci., 32,
1803-1825.
CREER K.M. (1975). On a tentative correlation between changes in a geomagnetic polarity bias and reversal frequency and the Earth’s rotation
through Phanerozoic time. In Growth Rhythms and The History of the Earth’s rotation. John Wiley, London.
CREER K.M., IRVING E. & RUNCORN S.K. (1954). The direction of the geomagnetic field in remote epochs in Great Britain. J. Geomag. Geoelect.,
6, 163-168.
CULOTTA R.C., PRATT T. & OLIVER J. (1990) -A tale of two sutures: COCORP’s deep seismic surveys of the Grenville Province in the east US
midcontinent. Geology, 18, 646-649.
DALLMEYER R.D., D’LEMOS R.S. & STRACHAN R.A. (1992) -Timing of post-tectonic Cadomian magmatism on Guersey,Channel Islands: evidence
from Ar-40/Ar-39 mineral ages. J. Geol. Soc. Lond., 149, 139-147.
DZIEWONSKI A.M. (1984) -Mapping the lower mantle: determination of lateral heterogeneity in P velocity up to degree and order 6. J. Geophys.
Res., 89, 5929-5952.
EMSLIE R.F. (1985) -Proterozoic anorthosite massifs. In The Deep Proterozoic Crust in the North Atlantic Provinces, Dordrecht (Reidel).
EØTVØS R. (1913) -In Verhandlungen der 17. Allgemeinen Konferenz der Internationalen Erdmessung, Part I.
FORTE A.M., DZIEWONSKI A.M. & O’CONNELL R.J. (1995) -Conti-nent-ocean chemical heterogeneity in the mantle based on seismic tomography.
Science, 268, 368-388.
GOLDREICH P. & TOOMRE A. (1969) -Some remarks on polar wandering. J. Geophys. Res., 74, 2555-2567.
GOTTFRIED R. (1990) -Origin and evolution of the Earth - chemical and physical verifications. In Critical Aspects of the Plate Tectonics Theory
II, Theophrastus Publ., Athens (Greece).
GOWER C.F., RYAN A.B. & RIVERS T. (1990) -Mid-Proterozoic Lau-rentia-Baltica: an overview of its geological evolution. In Mid-Pro-terozoic
Laurentia-Baltica, Geol. Assoc. Can.
GREEN A.G., MILKEREIT B., DAVIDSON A. et alii (1988) -Crustal structure of the Grenville Front and adjacent terranes. Geology, 16, 788-792.
GREGORI G. (2001) -The origin of the magnetic field and the endogeneous energy of the Earth and planetary objects (extended abstract). Int.
Workshop on Global Wrench Tectonics, Oslo 9-11 May, 2001.
HUNT C.W. (1992) -Expanding Geospheres. Energy and Mass Transfers from Earth’s Interior. Polar Publishing, Calgary.
JACKSON H.R., MARILLIER F. & HALL J. (1998). Seismic refraction data in the Gulf of Saint Lawrence: implications for the lower-crustal blocks.
Can. J. Earth Sci., 35, 1222-1237.
KREICHGAUER P.D. (1902) -Die Äquatorfrage in der Geologie. Missionsdruckerei, Steyl.
LEUNG I., GUO W., FRIEDMAN I. & GLEASON J. (1990) -Natural occurrences of silicon carbide in a diamondiferous kimberlite from Fuxian.
Nature, 346, 352-354.
LEVY E.H. (1987) -Energetics of chondrules formation. In Meteorites, Univ. of Arizona Press, Tucson.
LUPTON J., BAKER E., EMBLY R., GREENE R. & EVANS L. (1999) Anomalous helium and heat signatures associated with the 1998 axial volcano
event, Juan de Fuca Ridge. Geophys. Res. Lett., 26, 3449-3452.
MACDONALD G.J.F. (1964) -The deep structure of continents. Science, 143, 921-929.
MCLAUGHLIN-WEST E.A., OLSON E.J., LILLEY M.D., RESING J.A., LUPTON J.E. & BAKER E.T. (1999) -Variations in hydrothermal methane and
hydrogen concentrations following the 1998 eruptions at Axial Volcano. Geophys. Res. Lett., 26, 3453-3456.
MELTON C.E. & GIARDINI A.A. (1974) -The composition and significance of gas released from natural diamonds from Afrika and Brazil. Am.
Mineraligist, 59, 775-782.
MILLER H.G., STORETVEDT K.M. & SCHEIDEGGER A.E. (2001) -The main structural trends of Newfoundland: interpretation within a new
dynamo-tectonic framework. Proc. Int. Workshop on Global Wrench Tectonics, Oslo 9-11 May, 2001.
MORELLI A. & DZIEWONSKI A.M. (1987) -Topography of the core-mantle boundary and lateral homogeneity of the liquid core. Nature, 325,
678-683.
MUNK W.H. & MACDONALD G.J.F. (1960) -The Rotation of the Earth. Cambridge Univ. Press, Cambridge.
NEUBAUER F., FRISCH W., SCHMEROLD R. & SCHLÖSER H. (1989)
Metamorphosed and dismembered ophiolite suites in the basement units of the Eastern Alps. Tectonophysics, 164, 49-62.
OKUCHI T. (1997) -Hydrogen partitioning into molten iron at high pressure: implications for Earth’s core. Science, 278, 1781-1784.
POIRIER J.-P. (2000) -Introduction to the Physics of the Earth’s Interior. Cambridge Univ. Press.
POWER G.M., BREWER T., BROWN M. & GIBBONS W. (1990) -Late Precambrian foliated plutonic complexes of the Channel Islands and La Hague:
early Cadomian plutonism. In The Cadomian Orogeny, Geol. Soc. London.
RUNCORN S.K. (1955) -Rock magnetism – geophysical aspects. Adv. in Physics, 4, 244-291.
SCHAERER U. & GOWER C.F. (1988) -Crustal evolution in eastern Labrador: constraints from precise U-Pb ages. Precamb. Res., 38, 404-421.
SCHEIDEGGER A.E. (1995) -Geojoints and geostresses. In Mechanics of Jointed and Faulted Rock, Balkema, Rotterdam.
STARMER I.C. (1993) -The Sveconorwegian orogeny in southern Norway, relative to deep crustal structures and events in the North
Atlantic Proterozoic Supercontinent. Norsk Geol. Tidsskr., 73, 109-132.
STEVENSON D.J. (1981) -Models of the Earth’s core. Science, 214, 611-619.
STORETVEDT K.M. (1990) -The Tethys Sea and the Alpine-Himalayan orogenic belt; megaelements in a new global tectonic system.
Phys. Earth Planet. Inter., 62, 141-184.
STORETVEDT K.M. (1992) -Rotating plates: new concept of global tectonics. In New Concepts in Global Tectonics, Texas Tech. Univ. Press,
Lubbock.
STORETVEDT K.M. (1997) -Our Evolving Planet. Alma Mater (Fagbokforlaget), Bergen.
STORETVEDT K.M. (2003) -Global Wrench Tectonics. Fagbokforlaget, Bergen.
TSUCHIDA Y. & YAGI T. (1989) -A new post-stishovite high-pressure polymorph of silica. Nature, 340, 217-220.
TU´ NYI I., GUBA P., ROTH L.E. & TIMKO M. (2001) -Shock magnetic field and origin of the Earth and the planets (extended abstract). Int.
Workshop on Global Wrench Tectonics, Oslo 911, 2001.
TU´ NYI I., GUBA P., ROTH, L.E. & TIMKO M. (2004) -Electric Discharges in the Protoplanetary Nebula as a Source of Impulse Magnetic Fields to
Promote Dust Aggregation. Earth, Moon and Planets, 93, 65-74.
WALDRON J.W.F., ANDERSON S.D., CAWOOD P.A., GOODWIN L.B. & HALL J. et alii (1998) -Evolution of the Appalachian Laurentian margin:
Lithoprobe results in western Newfoundland. Can. J. Earth Sci., 35, 1271-1287.
WEGENER A.L. (1929, translated and reprinted 1966) -The Origin of Continents and Oceans. Dover, New York.
WELHAN J.A. & CRAIG H. (1983) -Methane, hydrogen and helium in hydrothermal fluids at 21º N on the East Pacific Rise. In Hydrothermal
Processes at Seafloor Spreading Centres, Plenum Press, New York.
WINDLEY B.F. (1995) -The Evolving Continents. John Wiley & Sons, Chichester (UK).